1. Technical Field
The present invention is related to the interconnection of electronic devices. More particularly, this invention is related to a mounting scheme that allows the blind mating of electrical connectors in a tray to electrical connectors in a module that is inserted into the tray.
2. Background Information
Electrical connectors are used to interconnect electrical devices. There are many different types of electrical connectors in use today. For example, D-sub connectors are well-known in the part: they are very common, for example, in personal computers. A typical personal computer system contains several D-sub connectors, including serial ports, parallel printer ports, connections for a monitor, and game ports.
The operation of prior art D-sub connectors is shown in FIG. 1. FIG. 1 shows an exemplary pair of D-sub connectors that mate with each other. Female connector 100 is a connector with fifteen holes 102. Each hole 102 may be connected to a lead to transmit and receive signals. Flange 104 surrounds the holes. Male connector 110 is a connector has fifteen pins 112. It should be understood that female connector 100 need not have fifteen holes and male connector need not have fifteen pins. D-sub connectors are available with a wide range in the number of holes and pins available: 9-pin connectors and 25-pin connectors are also common. Each hole 102 may be connected to a lead to transmit and receive signals. Flange 114 surrounds the pins.
To establish a connection between female connector 100 and male connector 110, one typically places flange 114 of male connector 110 such that it surrounds flange 104 of female connector 100 so that pins 112 are aligned with holes 102. When male connector 110 is coupled to female connector 100, several lines of communication will be established through a single connector. Typically, screws 116 and 118 may be provided in proximity with male connector 110 (e.g., within approximately 1 cm) such that screws 116 and 118 fit into nuts 106 and 108, which are in proximity with female connector 100. Screws 116 and 118 can be secured with nuts 106 and 108 so as to prevent an accidental disconnection.
Typically, after a user connects the D-sub connectors together, one can tighten the connection using screws. This tightening ensures that the connection is secure and the connection will not terminate inadvertently.
In certain situations, however, one is not able to manually secure such a connection. For example, certain aircraft systems, such as avionics and communications hardware, may be placed in modules that are inserted into trays contained that are located inside panels located in various areas of the aircraft, including the cockpit. The construction of these modules usually places connectors at the rear of the modules. The corresponding connectors are located at the rear of the tray in a wiring harness. Because of the placement of these connectors, access to the connectors may be restricted.
In an aircraft, modules are typically inserted into trays that are fixed in the cockpit and various other areas of the aircraft. FIG. 2 illustrates an exemplary tray 200 into which a module is inserted. Tray 200 includes rear plate 210. Attached to rear plate 210 is connector 212. It should be noted that a rear plate may contain a plurality of connectors. To simplify the illustration of the tray, however, only one connector has been illustrated in FIG. 2.
Referring now to FIG. 3, module 300 is illustrated as containing a display 302. It should be understood, however, that there are many different types of modules with many different types of functions available. The modules typically contain one or more connectors located at the rear of the modules, such as connector 304. Connector 304 connects with connector 212, located on rear plate 210 of tray 200. In order to couple connector 304 with connector 212, module 300 is inserted into tray 200.
One prior art method of inserting a module into a tray is as follows. A technician pulls a portion of the wiring harness out with the module and manually connects and secures the cables to the module. Thereafter, the module would be inserted into the tray. This can be a tedious process that may lead to several problems. For example, in pulling out the wiring harness to make the connection and inserting the module into the tray, it is possible to bend or break the cables. In addition, if the wiring harness is not correctly placed back into the tray, the module may not insert fully into the tray. Furthermore, the designers of the trays would have to provide room behind the tray for the slack of the wire to be stored when the module is fully inserted.
Because of the location of the connectors, it is impractical to visually align module 300 with tray 200 while inserting the module. It is therefore desirable to provide a device and technique to align the connectors blindly.
One prior art device for implementing a blind-mating technique is illustrated in FIG. 4A. Similar to the connectors of FIG. 1, connector 400 contains a flange and a plurality of pins. Corresponding connector 402 also contains a flange and several holes. In order to allow a user to connect the module with the tray without manually manipulating the connectors, connector 402 contains guide pins 410 and 412. The corresponding connector contains through holes 414 and 416 that align with guide pins 410 and 412, respectively. The guide pins may or may not be tapered such that the end that first comes into contact with the through holes is the narrowest portion and the pin is thicker closer to connector 402. As guide pins 410 and 412 first contact through holes 414 and 416, the connectors start to become aligned with each other. As the connectors are pushed towards each other, the thicker portion of the guide pins is in contact with through holes 414 and 416. The thicker portion of the guide pins has less freedom of movement within through holes 414 and 416. Thus, there is a closer alignment between the connectors before the respective flanges interconnect.
Connector 400 of FIG. 2 may be rigidly attached to the tray. Thus, connector 402 must move to the position of the connector 400 in order for the connection to occur. Because connector 402 is rigidly attached to the module, the entire module must be moved in order for the connectors to be aligned. Because of manufacturing inefficiencies, there are instances in which such an alignment is not possible.
Float bushings 420 may also be added to connector 400. Float bushings 420 allow connector 400 to move or xe2x80x9cfloatxe2x80x9d within certain limits. Thus, the addition of float bushings adds tolerances to the connector system. Instead of only moving connector 410 to align with connector 400 as with the system without the float bushings, both connectors 400 and 410 move with respect to each other to establish a connection.
While the addition of float bushings 420 allows movement in two mutually perpendicular directions, there is no provision for movement in the front-back direction, the direction of the insertion of the module. This can lead to some problems with misalignment. Because of manufacturing tolerances, the front-back dimension of the modules are not always the same. Therefore, when a module is inserted into a tray, there may be a portion of the front of the module (the xe2x80x9cbezelxe2x80x9d) that protrudes from the face of the tray. Furthermore, there may be a situation where the module, when inserted fully into the tray, is not as long as required. Therefore, the connectors may not fully engage with each other and are more easily disconnected from one another due to vibrations, movement, accidental bumping, etc.
In addition, the use of float bushings may result in a connector that is no longer centered within its mounting holes. Because a typical tray and module are mounted such that the connectors are vertically oriented, the float bushings tend to settle at the bottom of the hole in which it is mounted.
With reference to FIG. 4B, float bushing 450 rests within mounting hole 452. A connector would be mounted by a bolt through the center of float bushing 450. It is evident that the float bushing configuration is merely the placement of a bushing in a mounting hole that is larger than the float bushing. The float bushing thus has the capability to move throughout the mounting hole. However, because of gravity, float bushing 450 rests at the bottom of mounting hole 452. The result of this phenomenon is that there is no freedom of movement towards the bottom of mounting hole 452. Thus, when guide pins 410 and 412 are inserted into guide holes 414 and 416, the freedom of movement of connector 420 is limited.
For the foregoing reasons, there is a need for a connector setup that allows users to insert a module into a tray without having to manually connect the cables. There is also a need for a connector setup in which there is no need to pull the wiring harness out of the tray to establish a connection.
The present invention is directed to an apparatus that satisfies those and other needs. An apparatus having features of the present invention includes a tray containing a rear hole. There is also a fastener mounted in the rear hole with a spring mounted on the fastener. A mounting plate is further attached to a connector and the mounting plate is mounted on the fastener and the spring.
The fastener may be set up such that the fastener floats within the rear hole by having a fastener which is smaller than the rear hole.
There may also be a guide pin located on the rear plate.
A module having features of the present invention for insertion into the tray contains a connector and a guide hole located in proximity to the connector. Ideally, the guide hole is configured such that the insertion of the module into the tray results in the guide hole interfacing with the guide pin.
An alternative embodiment of the present invention contains guide pins on the module. Then the tray contains mounting holes located on the mounting plate. Therefore, the guide pins on the connector of the module interface with the guide holes on the connector of the tray.